Conventional straight-line potentiometers basically comprise a case with a longitudinal opening having at the sides thereof one or more electric slideways that are parallel to each other, and electroconductive and/or electroresistive, there being generally an electroconductive one for each electroresistive one, as well as a carrier with an operating stem or appendage that is operable to be shifted in a straight-line along the opening, the carrier carrying one or more electroconductive members or sliders forming jumpers between several points of the slideways.
In a known solution of the prior art, the engagement of the slider carrier with the potentiometer casing is carried out by means of two U-shaped or fork-shaped resilient lugs of the carrier, each of the lugs ending in a toe, the toes approaching when being inserted through the longitudinal opening and again spacing themselves apart once having passed the inner surface of the latter, the toes being thus retained at respective inner edges of the longitudinal opening. The electroconductive member forming the slider is attached to the fork-shaped lugs by means of riveting on flat fastening areas at both sides of the lugs, this operation having to be carried out by means of precision robotics due to the reduced dimensions involved. This increases the cost of the product if a correct manufacture of the potentiometer must be guaranteed.
Nevertheless, in the straight-line potentiometer of the prior art, it happens that if any intervention in the pertinent circuit or during the riveting process of the slider, the lugs approach or are deformed by heating, their toes can get at least in part into the longitudinal opening, thus being trapped inside it and preventing the operation of the potentiometer itself. And, if an attempt is made to unblock the carrier by acting on it in order to correct such an anomaly, the slider can be then damaged due to its frail build on account of its reduced dimensions. The gripping provided by said lugs, to a portion of which the slider is fastened by riveting, is not in any case effective or secure, and imposes in any case onerous process costs if a proper completion of the potentiometer is called for.